Bumblebee Specialist Group Report 2015 Edited by Paul Williams (Chair, UK) and Sarina Jepsen (Deputy Chair, USA) BBSG IN 2015 The BBSG exists to foster the conservation of bumblebees and their habitats around the world. In this fourth report of the BBSG’s activities, 2015 has been the best year so far, with accelerating progress towards our goal of evaluating the extinction risk of all ca 260 species of bumblebees worldwide using the IUCN Red List Criteria. Red List assessments have now been made for all of the European bumblebees plus 79 New World species. Congratulations to everyone on the results of all of their hard work! iucn.org/bumblebees 1 New BBSG Group for the South East Asian Region Map of BBSG regions, with the new South East Asian Region shown in orange. It is great news to be able to welcome the new regional group for South East Asia, led by Dr Panuwan Chantawannakul of Chiang Mai University, Thailand, and including colleagues, Dr Pham Hong Thai of the Vietnam National University of Agriculture, and Dr Jonathan Koch, working on the Philippine fauna from the University of Hawaii at Hilo, USA. Details of the progress that they are already making are given in their report below. Mexico workshop 2015 Red Listing Workshop for Mesoamerican and South American groups of the BBSG in Chiapas, Mexico. 2 In the Spring of 2015, the BBSG held a workshop to help in completing Red List assessments of the threat status of the bumblebee species in Mesoamerica and South America. This was run as part of the Mesoamerican Congress on Native Bees in San Cristóbal de Las Casas, Chiapas, Mexico. We are enormously grateful to Rémy Vandame and his team at ECOSUR, who organised and hosted the workshop so comfortably and so amiably. We also very much appreciate the support of CONABIO (Mexico) and IUCN and for funding the workshop. Seven members of the BBSG from Mesoamerica and two members of the BBSG from South America met to share knowledge of assessment methods and data. The BBSG Red List Authority and Xerces Society Conservation Biologist Rich Hatfield, BBSG Chair Paul Williams, and IUCN Species Survival Commission staff member Jennifer Luedtke led the workshop. Since the workshop, the members of the BBSG from Mesoamerica, working in cooperation with the Xerces Society and other members of the BBSG, have published nine bumblebee Red List assessments for Mesoamerica. The remaining three species assessments have been submitted to the IUCN for final review and publication. Members of the BBSG from South America, working in cooperation with the Xerces Society staff and other BBSG members, have published one bumblebee species assessment, and the remaining 21 species assessments have now been submitted to the IUCN for final review and publication. BBSG Red Listing Workshop in Mexico pushing back the frontiers. 3 Red Listing the bumblebees of the Americas Rich Hatfield / Sarina Jepsen / Rémy Vandame / Carolina Morales / Sheila Colla / Robbin Thorp / Paul Williams Bombus opifex enjoying a swim in a pink ocean of ornamental flowers at Sierras de Córdoba, Central Argentina. (Photo Carolina Morales.) This past year was especially productive for the BBSG in the Americas. We completed the evaluation of the extinction risk of all 79 species of bumblebee from North America, Mesoamerica and South America using the Red List Criteria and completed written assessments for each species. To complete each assessment, we have produced maps of the distribution of each species and compiled information on taxonomy, distribution, population status, habitats and ecology, use and trade, threats, conservation actions, and rationale for assigning each Red List category for all 79 bumblebee species of the New World, and entered that information into IUCN’s Species Information System (SIS). Forty-five species assessments from the New World have been published on the Red List to date, and the remaining 34 species assessments have been submitted to the Red List and will be published during the first update in 2016. 4 Pie chart showing the number of bumblebee species in each Red List Category for the New World Taken together, around one-quarter of the bumblebees in the New World are in a Red List threatened category – from Near Threatened to Critically Endangered. In the New World five species are listed as Critically Endangered, and three of those species are cuckoo bumblebees. Although this finding is new, it is not surprising, since cuckoo bumblebees are dependent upon other bumblebees as hosts, and some of the most endangered cuckoo bees co-occur with host species that are also threatened with extinction. Another conclusion from this work is that half of the species of bumblebees in South America have relatively poorly understood ranges – yet they are clearly experiencing continuing threats related to habitat loss and climate change. Many of these species are poorly understood and have relatively narrow historical ranges and, if patterns from North and Mesoamerica hold, may experience undocumented declines. A priority for further work will be to conduct regional surveys in South America to understand better the conservation status of these important animals. 5 Pie charts showing the number of bumblebee species in each Red List category for each region of the New World In North America, we used a database of nearly 300,000 geo-referenced North American bumblebee records, assembled from approximately 150 academic, research, citizen science, and private collections (for a list of data contributors see: http://www.leifrichardson.org/bbna.html), we evaluated changes over the past decade in each species’ extent of occurrence (EOO), persistence, and relative abundance. We used the results of these analyses to apply the Red List Criteria and assign Red List Categories to 46 species of North American bumblebees. We invited peer-review of the analytical methods and application of the Red List Criteria from the Chair and the 20 North American members of the BBSG and adjusted our analyses and/or interpretation of those analyses based on that feedback. We have also coordinated with bumblebee specialists in Mesoamerica (i.e.from Mexico to Panama) to obtain all available distribution information for the six species that occur in in both North and Mesoamerica. Using this information, we evaluated the entire geographic range of these species. In Mesoamerica, the BBSG compiled a database of over 24,000 geo-referenced records of bumblebees, including an extensive survey effort undertaken by Rémy Vandame and his team at ECOSUR since 2013 to document the current range of Mesoamerican bumblebees. Historical data were provided by more than 40 individuals and institutions, and describing specimens held in at least 15 collections around the world (a list of data contributors is available at: http://www.ecosur.mx/beesofmesoamerica/). With assistance from the Xerces Society the Mesoamerican BBSG applied the methods developed for the North American assessments to conduct robust quantitative assessments on the twelve species of bumblebees endemic to that region. Ten more species of the region were Red List assessed as parts of the 45 species assessed in North America, since they occur in both regions. In South America, the BBSG compiled the knowledge of several bumblebee experts throughout South America to assess the status of the 22 species of bumblebees endemic to that region. Despite considerable effort, little is known about many of the species, especially those with historically small, or remote ranges. It is clear that a concerted effort is needed to document the current distribution and conservation status of these important animals. This is especially true as some evidence suggest that additional species, such as B. bellicosus, are likely to be in peril. This species has undergone dramatic declines in the northern part of its range in Brazil, but very little is known about its distribution in the remainder of its range in Paraguay, Uruguay, and Argentina – making a global assessment of its status nearly impossible. One species from South America that is well-documented, and has experienced 6 dramatic declines likely due to the introduction of two non-native bumblebees, is B. dahlbomii (Red List Category: Endangered). This species’ assessment was published in 2015. Challenges. There has been much discussion about using the current IUCN assessment process for the assessment of invertebrates that have broad distributions and limited data. The issue with bumblebees is compounded because unlike many other Red Listed invertebrates most bumblebees are broadly distributed—not rare endemics. The lack of data on the decline for these species mandated that we take a different approach to these assessments. In North and Mesoamerica we used large databases to evaluate changes over the past decade in each species’ extent of occurrence, persistence, and relative abundance. This allowed us to prepare robust, data-rich assessments. In addition, we solicited feedback from multiple bumblebee specialists. We believe that we have created a process and a product that is fully supported by the bee research community, and that will be very useful to both the scientific and bee conservation communities. In fact, this assessment methodology is being adopted to assess a large group of stingless bees in Mexico and Mesoamerica as a result of the workshop that we conducted at the Mesoamerican Congress on Native Bees. The lack of available information for the distribution of South American bumblebees was another challenge for these assessments. To our knowledge, comprehensive recent survey work has not been conducted, and many historical records have not been digitized, or re- examined to confirm identification. Several morphologically similar species in South America have all-black color patterns, which makes identification challenging. Many of these specimens need re-examination before a clear assessment of conservation status can be conducted. While these assessments can currently be considered complete, there are likely revisions that will be needed in the near future.